HAL_Delay works and doesn't work

[NNar]

I'm still very new to STM32 processors, and using CubeMX to generate my basic code structure (for TrueStudio). In the code below, if I uncomment code section A, the yellow LED blinks, but not evenly...

• At low values such HAL_Delay(100), the high time is always 100 or 101ms, but the low time is sometimes 100ms and sometimes 87ms.
• At higher values, such as HAL_Delay(500), the high time is consistently 390ms and low time is less than 1ms.
• Using HAL_Delay(1000) instead gives me the same results as HAL_Delay(500);

What am I missing here?

Now, if I comment out section A, so that section B runs, the red LED comes on, but then the code hangs at the HAL_Delay(1000) so the yellow LED never comes on. If I drop that to HAL_Delay(100), the red LED comes on again, but the yellow LED blinks at approx 2.5Hz. There are no other timers or interrupts running.

I don't know what to check next. If this is somehow expected behaviour, which doc explains how this is supposed to work?

Thanks

/* USER CODE BEGIN 2 */
 
//  HAL_TIM_Base_Start_IT(&htim17);
 
  // Code section A...
  while (1)
  {
	  HAL_GPIO_TogglePin(IENC1_GPIO_Port, IENC1_Pin);		// Toggle yellow LED
	  HAL_Delay(500);
  }
 
  // Code section B...
  HAL_GPIO_WritePin(IENC0_GPIO_Port, IENC0_Pin, GPIO_PIN_SET);		// Red LED on
  HAL_Delay(1000);
  HAL_GPIO_WritePin(IENC1_GPIO_Port, IENC1_Pin, GPIO_PIN_SET);		// Yellow LED on
  while(1);
 
  ...

[Tesla DeLorean]

HAL_Delay typically depends on the SysTick interrupt, that it fires and is configured correctly. Usually via HAL_Init()

I'd suspect the tool chain or generated code.

Review what else is on the pin.

[S.Ma]

If you use HAL_Delay inside an interrupt routine, havok behaviour may be seen. Check your ISRs and callbacks if any outside the shared code extract.

[NNar]

Thanks Clive. I completely re-created the project in CubeMX in a new directory, with a new name. All I have set is SWD enabled and 2 outputs for the LEDs. And I set the FCLK to 48MHz. Image below shows what I have. That's all. No other timers or peripherals enabled. Same exact behaviour.

I'm going to see if I can download an older version of CubeF0 to see if that makes a difference.

[NNar]

I have no interrupts set. See my response below to Clive about my configuration.

Thanks.